Effects of dehorning by amputation on oxidant-antioxidant status in mature cattle

Dehorning of cattle is a routine husbandry practice which improves the safety of stock handlers and reduces injury, bruising of carcasses and damage to hides, but methods of dehorning are probably painful and stressful. The aim of the study was to evaluate the stress response and the oxidant /antioxidant equilibrium against dehorning process by amputation performed under local anaesthesia in mature cattle. Blood malondialdehyde (MDA) and glutathione (GSH) concentrations, plasma Cortisol, nitric oxide (NO), glucose and cholesterol concentrations as well as plasma total antioxidant activity (AOA) were measured in 6 female Holstein cattle one hour before dehorning procedure and immediately after. Circulating MDA, NO and Cortisol concentrations were dramatically increased compared to initial values after dehorning whereas AOA and GSH concentrations were significantly depressed. Glucose concentrations significantly increased after dehorning, while the plasma cholesterol concentrations significantly decreased. These results demonstrate that MDA, NO, AOA and GSH are the most powerful markers for evaluating the oxidant/antioxidant status in mature cattle and that dehorning was a stressful situation leading to an oxidative stress which can be amplified by strong glucocorticoid secretion